Highlights Radioactivity in soil sediments of Iju River was found to be within the limit level. Excess lifetime cancer risks on human and ecosystem found to be higher slightly in some sites. Activity utilization index from gamma radiation of natural radionuclides found to be within the permissible level.

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This review article briefly explores the significance of electromagnetic method among other methods used in groundwater investigation. Groundwater investigation can be carried out using various methods such as seismic, magnetic, electromagnetic (EM), electrical resistivity, gravity, remote sensing. Each with its peculiar implication. This paper discusses the effectiveness of EM in detail subsurface investigation for groundwater exploration through an extensive review of the literature. Relevant literatures within the last three years were considered to understand the groundwater features using the EM method over other techniques. Studies using other methods were also examined to compare their reliability in groundwater studies to EM method. This study discovered that the EM method is cheaper, faster and of higher precision in identifying groundwater bearing formation and possible structural control of which the rest technique do not posess such attribute. On this note, there should be a growing interest in the use of EM techniques for groundwater mapping, which gives credible and classification of structural features of both basement and sedimentary terrain groundwater characteristics.

The radioactivity levels were measured using a hand-held gamma-ray survey meter and NaI (Tl) based gamma spectroscopy to evaluate the seasonal variation of radioactivity levels in the riverine area of Ado-Odo Ota. The measured iso-dose map reported higher gamma dose rate of 79 nGy/h, approximately 34% higher than the world average of 59 nGy/h. The values for U-238, Th-232 and K-40 activity levels ranged between 29.9 and 21.6; 103.2 and 31.2; 802.2 and 233.5 with mean values of 26.1, 55.6 and 499.3 Bq/kg, respectively. According to the mean, 5th and 95th percentiles of the probabilities using the Monte Carlo simulation, the Radium equivalent activities and the absorbed dose rates are within their respective recommended limits of 370 Bq/kg and 84 nGy/h. This study could be used to monitor dose rates and radiological risks for the areas covering the small area (Ado-Odo Ota) to the larger area (West African Region) as baseline data.

The poor access to water quality for Nigerians has pushed for the designing of new trend silver nitrate impregnated locally made Point-Of-Use (POU) ceramic filters to enhance water purification efficiency for household use. This study utilized silver nitrate-molded ceramic filters prepared with Kaolin from Owode, silt soil, sodium silicate, sawdust, and distilled water in three varying proportions to ascertain pollution removal efficiencies. Heating was carried out by firing the filters at 900 °C and further preheating at 400 °C after dipping in silver nitrate solution. Silver nanoparticle and dissociated particle discharge from filter pot painted with 0.03 mg/g casein-covered nAg or AgNO 3 were estimated as an element of pH (5–9), ionic strength (1–50mM), and cation species (Na+, Ca2+, Mg2+). Silver delivery was constrained by disintegration as Ag+ and resulting cation exchange measures, paying little heed to silver structure applied. Water analysis for both heavy metals (Pb and Cd) and microbial load ( E. coli ) evaluated, corroborate the maximum removal efficiency. It was observed that kaolin-sawdust with the Silver nitrate filters showed a constant and effective removal of both heavy metals and disinfection of microbial loads. The minimum flow rates observed were 4.97 mL/min for batch filter used for Iju River water sample one (AF1) and 4.98 mL/min for batch filter used for Iju River water sample two (AF2) having porosity 49.05% and 50.00%, whereas the 5 mL/min higher flow rate was used for batch filter from borehole water sample one (BF1) and batch filter used for well water sample two (CF2) with porosity of 50.00%. Significantly, the results obtained show that the filters are suitable for point-of-use application in both the urban and rural areas of developing countries such as Nigeria